Surface type heat exchanger



. Jul .18, 1944. SMHH 2,354,071

' 4 SURFACE TYPE HEAT EXCHANGER Filed Jan. 1, 1942 Inventor:

W MW His Attorney.

Arthur R. Smit h,

Patented July 18, 1944 suarncn TYPE HEAT EXCHANGER Arthur R. Smith,Schenectady, N. Y., assignor to General Electric Company, a corporationof New York 1 Application Januaryl, 1942,Serial No. 425,307

' 4 Claims. (01. 257-43) v The present invention relates to surface typeheat exchangers such as are used as condenser boilers in mercury powerplants although it is not limited thereto necessarily. In condenserboilers mercury vapor exhausted from a turbine is condensed and the heatcontent of the vapor is transferred to water in order to produce steam.

The object of the 'present invention is to provide an improvedconstruction of surface type heat exchangers which may be effectivelyand efliciently operated as condenser boilers.

For a consideration of what I believe to be novel and my invention,attention is directed to the following description and the claimsappended thereto in connection with the accom. panying drawing.

In the drawing Fig. 1 illustrates a sectional view of a condenser boilerembodying my invention; and Fig. 2 is a section of Fig. 1. The righthandhalf of Fig. 2 is taken along line 22 of Fig. 1 and the left-hand halfof Fig. 2 is taken along line 3-3 of Fig. 1.

The arrangement comprises an outer fabri cated cylindrical shell or drumID with cupshaped end portions II and I2 fused to opposite endsof theshell ID. The shell'in the present example is horizontally disposed andhas an upper rportion forming an inlet |3 for receiving medium to becooled such as mercury vapor discharged from a turbine and to becondensed within the shell. A lower portion of the shell has two spacedopenings l4, |5ffor discharging cooled or condensed medium. In thepresent instance these openings are connected by conduits I6 and I1respectively to a mercury sumpl l8. The shell or container for hightemperature fluid is of relatively light weight and for this reasonreinforced by a plurality of axiallyspaced annular channel members or.loops i9, 20. Each channel member is sealed, in thepresent instancefused, to the outer wall of the shell Ill and the annular channels 2|formed between the channel members and the shell communicate with theinterior of the shell through a plurality of circumferentially spacedopenings 22 in the upper and lower portions of the shell. With thisarrangement heated medium is admitted through the upper openings- 22into the channels 2| whereby the channel members I9, are subjected tosubstantially the same temperature as the shell "I and the setting up ofexcessive temperature stresses is thereby avoided.

Two spaced plates 23 and 24 are disposed within the shell I0 on oppositesides of and oppositely inclined towards a vertical plane through thecenter of the shell. The plates 23, 24 form between them a condenserspace proper 25, that is, the space in which condensation or heattransfer is to take place. The purpose of oppositely inclining theplates is to produce a. space 25 which decreases in cross sectionalarea. in the direction of flow of vapor and thereby to assuresubstantially uniform condensation and constant velocity of the mediumto be condensed. Each of the plates 23, 24 extends along the entirelength of and is securely supported on the outer shell by means of aplurality of axially spaced perforated plates 26 having inner bent edgepor-v tions fastened to the plates by bolts 21 and outer curved edgesfused to portions of the shell l0 by welds 28. The plate 23 and anadjacent portion of the shell form a space 29. This portion of the shellis without perforations and the upper edge of the plate 23 has sealingcontact with the shell so that no fluid can enter directly from theupper part of the condenser space prorper 25 into the upper end of thespace 29. The lower end of the plate 23 is spaced from the adjacentportion of the shell forming a clearance 30 therewith, permitting fluidto pass from the lower portion of the space 25 into the lower portion ofthe "space 29. Similarly, the other plate 24 forms a space 3| with theshell and has an upper edge forming sealing contact with the shell and alower edge spaced from and forming a clearance with the shell.

Condensation of mercury vapor in the present example is effected by aplurality of spaced rows or banks of tubes. In the present instance Ihave shown eight spaced rows or banks of tubes 32 on each side of thevertical centerline of the drum. Each row of tubes consists of aplurality of series-connected substantially uniformly spacedhairpin-shaped tube portions 33 with an. inlet conduit 34 projectingthrough the bottom of the shell and connected to an inlet header 35, andwith an outlet or discharge conduit 36 projecting through the top of the:shell and connected'to an outlet or steam header 31. The hainpin-shapedtube portions have a diameter increasing from the inlet conduit towardsthe outlet conduit. In the present example the inlet half of each row oftubes has a uniform diameter smaller than the uniform diameter of theoutlet half of such row. Each row of tubes is inclined with respect tothe central vertical plane through the drum, with the inclination perrow increasing from the row of tubes nearest the central vertical planetowards the plates 23 and 24 respectively. Thus the rows or banks oftubes form passages between them for the fluid to be cooled or condensedand the cross sectional area of these passages decreases downwardly whenviewed in Fig. 2, that is, in the direction of flow of vapor. In otherwords, as condensation takes place the cross sectional area of thepassages for vapor is reduced to assure substantially uniform velocityof the medium to be condensed on its path throughthe condenser.

The spacing between the several rows of tubes is maintained by apluralit of spacer means:

In the present example this spacer means is in the form of verticallyspaced substantially horizontally disposed rods 38 with spacers 39 heldon the rod between adjacent rows of tubes. The upper rod 38 has endportions engaging and sup- I ings, and means for reinforcing thershellincludported on the upper ends of the plates 23, 24.

Lower hairpin-shaped portions of the tubes are held on supports 40, 4|and 42 secured to the shell I0. The hairpin-shaped tube portions of eachrow have looped or widened ends 43 engaging andsupporting each otherwith the ends of the lower tube portions resting on the supports 40 and42. r

Bafiles 44 are provided within the inlet HI and arranged uniformly todistribute vapor to. be condensed over the entire length of the tubes.Non-condensables such as airin the case of a condenser boiler may beremoved from the condenser through perforated tubes 45 and 46 locatedrespectively in lower parts of the spaces 29 and 3| formed between theplates 23 and 24 respectively and adjacent portions of the shell l0.

During operation mercury vapor is supplied to the condenser through theinlet I3 and this vapor is condensed as it is passed over the banks oftubes, the condensate being discharged r through theconduit 6, l1 intothe mercury sump l8. Non-condensables accumulating in the lower portionof the condenser space proper 25 pass through the clearances 3|]near'the lower ends of the plates 23 and 24 respectively and arewithdrawn through the perforated tubes and 46. Cooling medium, in thepresent] instance water, is forced by a pump 4! into an inlet 48 of thelower header 35, whence it is passed through the several banks or rowsof tubes'and evaporated; the vapor being discharged from the outletconduits 36 of the rows of tubes into the upper header 31 which latterhas a steam discharge conduit 49. Some of the mercury vapor passesthrough the openings 22 in the shell into the channels 2| and iscondensed therein, the condensate being discharged from lower portionsof the channels 2| through pipes 5|}, 5| connecting the lower portionsof the channels 2| with the aforementioned conduits I6, I"!respectively. The perforations or holes 22 connecting the lower portionof the shell with the channels 2| normally assure a continuous flow ofvapor through the channels 2|. In case the drain pipes 50, 5| becomeclogged, condensate is discharged from the lower portions of the channeling an annular channel member surrounding and fused to the shell andforming a channel com- "municati ng with the interior of the shellthrough a plurality of circumferentially spaced openings in the shell.

2. Condenser boiler comprising a cylindrical shell having a top portionforming an inlet for mercury vapor and a bottom portion forming anoutlet for mercury liquid, means for reinforcing the shell comprising aplurality of spaced annular channel members surrounding and sealed tothe shell, the shell having circumferentially spaced openings toestablish communication between the interior of the shell and thechannels formed by said channel members, two plates located within theshell on' opposite ides of and oppositely inclined towards a centralplane through the shell to define a condenser space proper between themdecreasing in cross sectional area in the direction of flow of mercuryvapor, spaced banks of tubes located within said space, and means forremoving non-condensables fromthe spaces defined between each of saidplates and the adjacent portions of the shell, ,the shell portionadjacent the plates being free from said circumferentially-spacedopenings to; preclude non-c'ondensables in the last named spaces fromflowing into the. channels;

3. A container for fluid at high temperature comprising a fabricatedcylindrical shell and'a reinforcing channel member surrounding andsealed to the shell, the shell having a plurality of circumferentiallyspaced openings to effect communication between the interior of theshell and the channel formed by the channel member in order to minimizerelative expansion between the shell and the channel member. I

4. Condenser boiler comprising a shell having an inlet opening forreceiving fluid to be condensed and an outlet conduit for dischargincondensate, a'channel member surrounding the, shell and fused theretoand perforations in the, shell to establish communication betweentheinterior of thechannel member and the interior of the shell, a pipefor conducting condensate from the channel member into said outletconduit, and' banks of spaced tubes disposed within the shell and havinginlets for receiving a cooling medium and outlets forjdischargingheatedmedium.

' ARTHUR R; SMITH.

